Field of the Invention
The disclosure is related the field of liquid crystal, and more particularly, to a mask plate, a photo-alignment method using the same and a liquid crystal display device.
Description of Related Art
In general, the most common alignment technology in manufacturing liquid crystal displays is rubbing alignment. By this method, liquid crystal molecules have better performance of alignment. However, during rubbing, static electricity and pollution generated by particles would occur because of the rubbing villus, which causes the damage of the liquid crystal units.
Currently, another photo alignment method is used. In this method, a linearly-polarized ultraviolet is irradiated to a polymer alignment film having sensitizer, so that the polymers are aligned. The advantage of this method is that the method can avoid the pollution on the surface of the glass substrate, alignment with a small area is feasible, alignment with patterns can be achieved by a photo mask, the properties of the liquid crystal unit, such as the pre-inclined angle, the strength of the surface orientation, can be controlled by the incident angle of the light and the exposure time.
However, in this method, when forming a plurality of regions having the same alignment in a plurality of sections in a pixel for increasing the side visibility, a plurality of photo masks is needed. In addition, the method needs to comprise a plurality of steps for irradiating light with different directions. Thus, the method is complicated and the cost is expensive.